Fuel nozzles

ABSTRACT

A nozzle includes a nozzle body defining a longitudinal axis. The nozzle body has an air passage, a fuel circuit radially outboard from the air passage with respect to the longitudinal axis, and a cooling circuit. The fuel circuit extends from a fuel circuit inlet to a fuel circuit annular outlet. The fuel circuit is defined between a fuel circuit inner wall and a fuel circuit outer wall. At least a portion of the fuel circuit outer wall is radially outboard from the fuel circuit inner wall with respect to the longitudinal axis. A cooling circuit is defined within at least one of the fuel circuit inner wall or the fuel circuit outer wall. The cooling circuit extends from an axial position proximate the fuel circuit inlet to an axial position proximate the fuel circuit outlet.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present disclosure relates to nozzles, and more particularly to fuelnozzles such as those used in combustors of gas turbine engines.

2. Description of Related Art

A variety of engines typically incorporate fuel injectors or nozzles intheir combustion sections in which fuel and air are mixed and combusted.Efficiency of combustion is related to a variety of factors includingfuel-to-air ratio, ignition source location and degree of fuelatomization. Fuel is typically sprayed from a pressure atomizer and thenmixed with flows of air. Fuel staging requires that some nozzles of thefuel injector are stopped from flowing fuel during a given mission. Lackof fuel flow and high combustion temperatures can make the nozzle proneto coking, especially those parts closest to the flame.

Such conventional methods and systems have generally been consideredsatisfactory for their intended purpose. However, there is an ongoingneed in the art for improved fuel nozzles. The present disclosureprovides a solution for this need.

SUMMARY OF THE INVENTION

A nozzle includes a nozzle body defining a longitudinal axis. The nozzlebody has an air passage, a fuel circuit radially outboard from the airpassage with respect to the longitudinal axis, and a cooling circuit.The fuel circuit extends from a fuel circuit inlet to a fuel circuitannular outlet. The fuel circuit is defined between a fuel circuit innerwall and a fuel circuit outer wall. At least a portion of the fuelcircuit outer wall is radially outboard from the fuel circuit inner wallwith respect to the longitudinal axis. A cooling circuit is definedwithin at least one of the fuel circuit inner wall or the fuel circuitouter wall. The cooling circuit extends from an axial position proximatethe fuel circuit inlet to an axial position proximate the fuel circuitoutlet.

The nozzle can include a stem operatively connected to a fuel manifoldof the nozzle body. The stem can include three liquid channels for fluidcommunication with at least one of the fuel circuit or the coolingcircuit. The three liquid channels can be a fuel channel in fluidcommunication with the fuel manifold to provide fuel to the fuel circuitinlet, a coolant-in channel in fluid communication with a distributionchannel of the cooling circuit to provide coolant thereto, and/or acoolant-out channel in fluid communication with the collection channelof the cooling circuit to receive coolant therefrom.

The cooling circuit can include a distribution channel in fluidcommunication with a coolant-in channel and a collection channel influid communication with a coolant-out channel. The distribution channeland the collection channel can be circumferentially spaced apart fromone another, and/or co-planar with one another. The cooling circuit caninclude a pair of helical threads. A first one of the helical threadscan begin at the distribution channel and extend to an axial positionproximate the fuel circuit outlet to provide cooling flow to the nozzletip. A first end of a second one of the helical threads can be connectedto the first helical thread proximate to the fuel circuit outlet and canextend to the collection channel to provide a cooling flow exit to thecoolant-out channel. The first end of the second one of the helicalthreads can be connected to the first helical thread through a shortcircuit segment.

The nozzle body can include a pair of tubes defined through the airpassage and though a fuel manifold, wherein one of the tubes fluidlyconnects the distribution channel to the cooling circuit inlet andanother one of the tubes fluidly connects the collection channel to thecooling circuit outlet. The air passage includes an annular inlet havingradial swirl vanes circumferentially spaced apart from one another. Thetubes can be defined within the radial swirl vanes. The air passage canbe defined between a backing plate and a fuel circuit inner walldownstream from the backing plate. At least a portion of the fuelcircuit inner wall can be a conical shape that converges toward thelongitudinal axis in a downstream direction. The air passage can includean annular inlet, a radial swirler, and/or a converging conicalcross-section. The radial swirler can include radial swirl vanescircumferentially spaced apart from one another about the annular inletto induce swirl into air entering the annular inlet of the air passage.

The nozzle body can include an outer air passage defined radiallyoutboard of the fuel circuit with respect to the longitudinal axis. Theouter air passage can be defined between a fuel circuit outer wall andan outer air passage wall. The outer air passage can be a convergingnon-swirling outer air passage. These and other features of the systemsand methods of the subject disclosure will become more readily apparentto those skilled in the art from the following detailed description ofthe preferred embodiments taken in conjunction with the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

So that those skilled in the art to which the subject disclosureappertains will readily understand how to make and use the devices andmethods of the subject disclosure without undue experimentation,preferred embodiments thereof will be described in detail herein belowwith reference to certain figures, wherein:

FIG. 1 is a cross-sectional side elevation view of a nozzle constructedin accordance with the present disclosure, showing the cooling circuitand the fuel circuit;

FIG. 2 is an enlarged cross-sectional side elevation view of a portionof the nozzle of FIG. 1, showing inner and outer fuel circuit walls;

FIG. 3 is a perspective view of the back side of the nozzle of FIG. 1,showing coolant-in and coolant-out channels in the stem;

FIG. 4 is a perspective view of a portion of the nozzle of FIG. 1,showing the circumferentially spaced apart coolant and fuel tubes;

FIG. 5 is a perspective view of a portion of the nozzle of FIG. 1,showing the tubes connecting with inner fuel circuit wall;

FIG. 6 is a perspective view of the back side of a portion of the nozzleof FIG. 1, showing the layer with the transfer tubes removed to show thedistribution channel and the collection channel within the inner fuelcircuit wall;

FIG. 7 is a perspective view of the front side of a portion of thenozzle of FIG. 1, showing the distribution channel and the collectionchannel within the inner fuel circuit wall connecting to the helicalthreads of the cooling circuit;

FIG. 8 is an enlarged perspective view from the front side of a portionof the nozzle of FIG. 1, showing the short circuit segment betweenhelical threads of the cooling circuit; and

FIG. 9 is an enlarged cross-sectional side elevation view of a portionof another nozzle constructed in accordance with the present disclosure,showing a cooling circuit in the outer fuel circuit wall.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Reference will now be made to the drawings wherein like referencenumerals identify similar structural features or aspects of the subjectdisclosure. For purposes of explanation and illustration, and notlimitation, a cross-sectional view of an exemplary embodiment of anozzle in accordance with the disclosure is shown in FIG. 1 and isdesignated generally by reference character 100. Other embodiments ofnozzles in accordance with the disclosure, or aspects thereof, areprovided in FIGS. 2-9, as will be described. The systems and methodsdescribed herein provide for radial swirl nozzles with increased coolingcapability, for example, the ability to cool an annular fuel distributoreven when the fuel distributor is not in use.

As shown in FIGS. 1 and 2, a nozzle 100 includes a nozzle body 102defining a longitudinal axis A. Nozzle body 102 includes a fuel circuit106 and a cooling circuit 105. Both circuits are radially outboard froman air passage 104 with respect to longitudinal axis A. Fuel circuit 106is defined between a fuel circuit inner wall 115 and a fuel circuitouter wall 116, e.g. the annular fuel distributor. It is contemplatedthat inner and outer fuel circuit walls 115 and 116, respectively, canbe made from a metallic material, and/or can be made monolithicallythrough additive manufacturing or casting. A portion of fuel circuitouter wall 116 is radially outboard from fuel circuit inner wall 115with respect to longitudinal axis A. A portion of both fuel circuitinner wall 115 and outer wall 116 are conically shaped and convergetoward longitudinal axis A. Fuel circuit annular outlet 110 is proximateto the outlet of air passage 104. Those skilled in the art will readilyappreciate that cooling circuit 105 can use fuel that can be returnedback to the fuel tank and/or fuel that is en route to an adjacent nozzlethat is in use, e.g. has fuel flowing from an inlet to an outlet. It isalso contemplated that cooling circuit 105 can use liquid coolant.

With continued reference to FIGS. 1 and 2, cooling circuit 105 isdefined within fuel circuit inner wall 115 extending from an axialposition proximate a fuel circuit inlet 108 to an axial positionproximate fuel circuit outlet 110. It is also contemplated that coolingcircuit 105 can be defined within fuel circuit outer wall 116, asdescribed below with respect to FIG. 9. Air passage 104 is definedbetween a backing plate 124 and a jacket 134 downstream from backingplate 124. Those skilled in the art will readily appreciate that backingplate 124 and jacket 134 can be made from thin metallic materials and/ora thicker ceramic material, such as a ceramic-matrix composite (CMC)material, e.g. jacket 134 can be an insulation jacket.

As shown in FIG. 1, air passage 104 includes a radial swirler 140 at anannular inlet 126. Radial swirler 140 has radial swirl vanes 128circumferentially spaced apart from one another about annular inlet 126to induce swirl into air entering air passage 104. Large swirl offsetand pure radial entry produces very high swirl and high radial pressuregradient at fuel outlet 110. A plurality of cylindrical fuel tubes 122are defined through air passage 104. Each fuel tube 122 connects arespective circumferentially spaced apart opening 118 of fuel circuitinlet 108 to a fuel manifold 120. Tubes 122 can be metallic transfertubes. It is also contemplated that in place of some of tubes 122,fasteners can also be used. Vanes 128, described above, can be hollowand/or ceramic, and insulate tubes 122 as they pass through air passage.

With continued reference to FIG. 1, an outer air passage 130 is definedradially outboard of fuel circuit 106 with respect to longitudinal axisA. Outer air passage 130 provides non-swirled air. Outer air passage 130is between a jacket 136 and an outer air passage wall 131. It iscontemplated jacket 136 and an outer air passage wall 131 can beconstructed using a thin metallic material and/or thicker ceramicmaterial, e.g. a CMC material. For example, jacket 136 can be a metallicshell and not provide any insulation and/or it can be a ceramic materialand be an insulation jacket to insulate fuel circuit 106. Insulationjackets can be made from a ceramic or a ceramic composite material, bothof which tend to reduce thermal growth mismatch. Metallic shells can bedesigned to mitigate thermal growth effects, e.g. by using slits,multiple pieces, growth gaps etc.

As shown in FIGS. 1 and 3, nozzle 100 includes a stem 107 operativelyconnected to fuel manifold 120 of nozzle body 102. Stem 107 includes afuel channel 109 in fluid communication with fuel manifold 120 toprovide fuel to fuel circuit inlet 108, shown in FIG. 2. Stem 107includes a coolant-in channel 111 and a coolant-out channel 123. Thoseskilled in the art will readily appreciate that while fuel manifold 120is shown integrally formed with backing plate 124, it can be formedindependent of backing plate 124. Those skilled in the art will readilyappreciate that embodiments of the present invention, e.g. nozzles 100,are easily manufactured radial swirlers that are lightweight. Nozzles100 and can be additively manufactured, for example using direct metallaser sintering, or the like. Moreover, components of nozzle body 102can be appropriately spaced to permit thermal expansion and contraction.

As shown in FIGS. 4-6, fuel circuit inner wall 115 includes a pair ofcylindrical coolant tubes 127 extending therefrom defined through airpassage 104 and though fuel manifold 120, as shown in FIG. 1. Coolingcircuit 105 includes a distribution channel 121 in fluid communicationwith coolant-in channel 111 and a collection channel 125 in fluidcommunication with a coolant-out channel 123. One of tubes 127 is acoolant-in tube 127 a. Coolant-in tube 127 a fluidly connects coolant-inchannel 111 to distribution channel 121 to provide coolant thereto.Another one of tubes 127 is a coolant-out tube 127 b. Coolant-out tube127 b fluidly connects to coolant-out channel 123 to collection channel125 to receive exiting coolant therefrom. From coolant-out tube 127 b,coolant can be returned to a storage tank, or if the coolant is fuel, itcan be passed on to a nozzle that is in operation, as described above.Distribution channel 121 and collection channel 125 arecircumferentially spaced apart from one another and are co-planar withone another. Tubes 127 are defined through radial swirl vanes 128,similar to fuel tubes 122, described above.

As shown in FIGS. 7 and 8, cooling circuit 105 includes a pair ofhelical threads 133 that form a helical cooling channel 139. A first oneof the helical threads 133 a begins at distribution channel 121 andextends to an axial position proximate fuel circuit outlet 110 toprovide cooling flow to the nozzle tip. A first end 135 of secondhelical thread 133 b is connected to first helical thread 133 aproximate to fuel circuit outlet 110 through a short circuit segment137. Second helical thread 133 b extends to collection channel 125 toprovide a cooling flow exit to coolant-out channel 123. This allows thecoolant to be fed from one port, e.g. coolant-in channel 111, andreturned to another port, e.g. coolant-out channel 123.

With reference now to FIG. 9, a portion of another nozzle body 202 isshown. Nozzle body 202 is similar to nozzle body 102, except thatcooling circuit 205 is defined in a fuel circuit outer wall 116. Thoseskilled in the art will readily appreciate that cooling circuit 205 caninclude a distribution channel in fluid communication with a coolant-inchannel, similar to distribution channel 121 and coolant-in channel 111,and a collection channel in fluid communication with a coolant-outchannel, similar to collection channel 125 and coolant-out channel 123.It is also contemplated that a nozzle body can include both coolingcircuits 205 and 105, e.g. a cooling channel on both sides of a fuelcircuit.

The methods and systems of the present disclosure, as described aboveand shown in the drawings provide for radial swirl nozzles with superiorproperties including increased cooling capability, even when fuel is notflowing through the fuel circuit of the fuel distributor. While theapparatus and methods of the subject disclosure have been shown anddescribed with reference to preferred embodiments, those skilled in theart will readily appreciate that changes and/or modifications may bemade thereto without departing from the spirit and scope of the subjectdisclosure.

What is claimed is:
 1. A nozzle, comprising: a nozzle body defining alongitudinal axis including: an air passage; a fuel circuit radiallyoutboard from the air passage with respect to the longitudinal axis, thefuel circuit extending from a fuel circuit inlet to a fuel circuitannular outlet, wherein the fuel circuit is defined between a fuelcircuit inner wall and a fuel circuit outer wall, wherein at least aportion of the fuel circuit outer wall is radially outboard from thefuel circuit inner wall with respect to the longitudinal axis; a coolingcircuit defined within at least one of the fuel circuit inner wall andthe fuel circuit outer wall, wherein the cooling circuit extends from anaxial position proximate the fuel circuit inlet to an axial positionproximate the fuel circuit outlet, wherein the cooling circuit includesa pair of helical threads; and a stem operatively connected to a fuelmanifold of the nozzle body, wherein the stem includes: a coolant-inchannel in fluid communication with a distribution channel of thecooling circuit, wherein the coolant-in channel is configured andadapted to provide coolant to the distribution channel, and acoolant-out channel in fluid communication with a collection channel ofthe cooling circuit, wherein the coolant-out channel is configured andadapted to receive coolant from the collection channel, wherein a firstone of the helical threads begins at the distribution channel andextends to an axial position proximate the fuel circuit outlet toprovide cooling flow to a tip of the nozzle, and wherein a first end ofa second one of the helical threads is connected to the first helicalthread proximate to the fuel circuit outlet and extends to thecollection channel to provide a cooling flow exit to the coolant-outchannel.
 2. A nozzle as recited in claim 1, wherein the stem includes afuel channel in fluid communication with the fuel manifold to providefuel to the fuel circuit inlet.
 3. A nozzle as recited in claim 1,wherein the distribution channel and the collection channel are at leastone of: circumferentially spaced apart from one another, or co-planar.4. A nozzle as recited in claim 1, wherein the first end of the secondone of the helical threads is connected to the first helical threadthrough a short circuit segment.
 5. A nozzle as recited in claim 1,wherein the nozzle body includes a pair of tubes defined through the airpassage and though the fuel manifold, wherein one of the tubes fluidlyconnects the distribution channel to the coolant-in channel and theother one of the tubes fluidly connects the collection channel to thecoolant-out channel.
 6. A nozzle as recited in claim 5, wherein the airpassage includes an annular inlet having radial swirl vanescircumferentially spaced apart from one another, wherein the tubes aredefined within the radial swirl vanes.
 7. A nozzle as recited in claim1, wherein the air passage is defined between a backing plate and thefuel circuit inner wall downstream from the backing plate, wherein atleast a portion of the fuel circuit inner wall is a conical shape thatconverges toward the longitudinal axis in a downstream direction.
 8. Anozzle as recited in claim 1, wherein the air passage includes a radialswirler, a converging conical cross-section, and an annular inlet,wherein the radial swirler includes radial swirl vanes circumferentiallyspaced apart from one another about the annular inlet to induce swirlinto air entering the annular inlet of the air passage.
 9. A nozzle asrecited in claim 1, wherein the nozzle body includes an outer airpassage defined radially outboard of the fuel circuit with respect tothe longitudinal axis.
 10. A nozzle as recited in claim 9, wherein theouter air passage is defined between the fuel circuit outer wall and anouter air passage wall, and wherein the outer air passage is aconverging non-swirling outer air passage.
 11. A nozzle, comprising: anozzle body defining a longitudinal axis including: an air passage; afuel circuit radially outboard from the air passage with respect to thelongitudinal axis, the fuel circuit extending from a fuel circuit inletto a fuel circuit annular outlet, wherein the fuel circuit is definedbetween a fuel circuit inner wall and a fuel circuit outer wall, whereinat least a portion of the fuel circuit outer wall is radially outboardfrom the fuel circuit inner wall with respect to the longitudinal axis;a cooling circuit defined within at least one of the fuel circuit innerwall and the fuel circuit outer wall, wherein the cooling circuitextends from an axial position proximate the fuel circuit inlet to anaxial position proximate the fuel circuit outlet; a stem operativelyconnected to a fuel manifold of the nozzle body, wherein the stemincludes: a coolant-in channel in fluid communication with adistribution channel of the cooling circuit, wherein the coolant-inchannel is configured and adapted to provide coolant to the distributionchannel, and a coolant-out channel in fluid communication with acollection channel of the cooling circuit, wherein the coolant-outchannel is configured and adapted to receive coolant from the collectionchannel; and a pair of tubes defined through the air passage and thoughthe fuel manifold, wherein one of the tubes fluidly connects thedistribution channel to the coolant-in channel and the other one of thetubes fluidly connects the collection channel to the coolant-outchannel.
 12. A nozzle as recited in claim 11, wherein the stem includesa fuel channel in fluid communication with the fuel manifold to providefuel to the fuel circuit inlet.
 13. A nozzle as recited in claim 11,wherein the distribution channel and the collection channel are at leastone of: circumferentially spaced apart from one another, or co-planar.14. A nozzle as recited in claim 11, wherein the cooling circuitincludes a pair of helical threads, wherein a first one of the helicalthreads begins at the distribution channel and extends to an axialposition proximate the fuel circuit outlet to provide cooling flow to atip of the nozzle, and wherein a first end of a second one of thehelical threads is connected to the first helical thread proximate tothe fuel circuit outlet and extends to the collection channel to providea cooling flow exit to the coolant-out channel.
 15. A nozzle as recitedin claim 14, wherein the first end of the second one of the helicalthreads is connected to the first helical thread through a short circuitsegment.
 16. A nozzle as recited in claim 11, wherein the air passageincludes an annular inlet having radial swirl vanes circumferentiallyspaced apart from one another, wherein the tubes are defined within theradial swirl vanes.
 17. A nozzle as recited in claim 11, wherein the airpassage is defined between a backing plate and the fuel circuit innerwall downstream from the backing plate, wherein at least a portion ofthe fuel circuit inner wall is a conical shape that converges toward thelongitudinal axis in a downstream direction.
 18. A nozzle as recited inclaim 11, wherein the air passage includes a radial swirler, aconverging conical cross-section, and an annular inlet, wherein theradial swirler includes radial swirl vanes circumferentially spacedapart from one another about the annular inlet to induce swirl into airentering the annular inlet of the air passage.
 19. A nozzle as recitedin claim 11, wherein the nozzle body includes an outer air passagedefined radially outboard of the fuel circuit with respect to thelongitudinal axis.
 20. A nozzle as recited in claim 19, wherein theouter air passage is defined between the fuel circuit outer wall and anouter air passage wall, and wherein the outer air passage is aconverging non-swirling outer air passage.